Recently, the general trends in designing electronic devices are toward small size, light weightiness and easy portability. Moreover, with increasing development of electronic industries, the internal circuitries of the electronic devices are gradually modularized. In other words, plural electronic components are integrated into a single circuit module. For example, a power module is one of the widely-used circuit modules. An example of the power module includes but is not limited to a DC-to-DC converter, a DC-to-AC converter or an AC-to-DC converter. After the electronic components (e.g. integrated circuits, capacitors, resistors, inductors, transformers, diodes and transistors) are integrated as a power module, the power module may be installed on a motherboard or a system circuit board.
Nowadays, an embedded package structure is widely adopted. The process of fabricating the conventional embedded package structure will be illustrated as follows. Firstly, an electronic component with at least one conducting terminal (e.g., an active component) is embedded within an insulation substrate. Then, at least one via is formed in the insulation substrate by a laser drilling process. After a conductive material is filled in the via, a conductive via is formed. Then, a conductive layer is formed on the insulation substrate and contacted with the conductive via. Then, a passive component is installed on the above structure, and the passive component is electrically connected with the electronic component. Since the passive component and the electronic component are electrically connected with each other through the conductive layer and the conductive via, the passive component and the electronic component are vertically arranged in a stack form. Under this circumstance, the layout area of the motherboard or the system circuit board is saved.
However, since the passive component, the electronic component and the conductive layer are arranged in the stack form, the overall thickness of the embedded package structure is large (e.g., larger than 1000 micrometer). In other words, the conventional embedded package structure is not suitable for an ultra-thin electronic product (e.g., a smart watch or a tablet computer).